Wednesday, January 13, 2016

So Eli was slumming over at Lucia's where Steve Mosher was doing his best tipsy Richard Tol imitation and the subject was the Cruz Pause 18 year no trend in the satellite record, when a thought occurred. (Ear tip to Tamino, also look at his follow on, Drift)

If the changes in temperature over short periods (like days or months or even annually)
track each other, even just in direction in the satellite and surface
records (so) then that is pretty
convincing evidence that the problem is a long term drift in one or the
other and that on the short term they are measuring the same thing.

So Eli hit Wood for Trees and compared the RSS land only record with CRUTEM4 between 2005 and 2015. (RSS offset by 0.25 K)

.
If there was significant random (not actual) variation in either record, one would expect that there would be many months when the two curves moved in opposite directions. There are a few, but it's a lot like finding the panda. From this we conclude that MSU and CRUTEM4 are consistent on a monthly and even an annual basis. It might be even more interesting to look at this on a daily basis and even match times and AMSU footprint areas

Thus if (see Nick Stokes) the long term trends diverge, and the short
term anomalies agree, that is pretty good evidence of systematic drift.
.
The surface record analysis is simpler and a drift would require
correlation between drifts at many stations using different instruments
that are calibrated on site.
.
Eli concludes that the drift is most likely in the AMSU satellites or the processing of the AMSU data.
Unanticipated aging of the receiver or the internal hot calibration target seems
to Eli most likely, although there might be something involving orbital
decay (less likely now because this caused a lot of trouble early on) or
even changing land/sea/ice patterns which affect the AMSU response.

Since there are four or five satellites carrying the AMSU units and there is a newer ATMS system, analysis of where the discrepancy enters would not be simple.

19 comments:

"The surface record analysis is simpler and a drift would require correlation between drifts at many stations using different instruments that are calibrated on site."

But Watts et al 2015 *have* found the surface station drift!

How soon we forget. Scratch that. How soon *you* forget. Since Watts et al's AGU poster *I* no longer subscribe to the common misperception of the surface temp data. C'mon, get with program .... it's heat sinks and microsites all the way down.

Any denialist worth his non-vaccination could tell you what is the matter with your logic. Changing "corrections" have been applied to the data. {and that is actually true for both surface and satellite date}.

It's at least possible that there is a real divergence between surface temperatures and the average over the troposphere and parts of the stratosphere measured by the satellites.

I'm desperately trying NOT to fall into those same types of arguments, but the 'slippery slope' of TLT trend denial is haunting me, seriously.

On another note though, I am looking at all the global indices systematically, doing some (well actually a lot of) lagged correlations between TLT and SAT (raw time series), some (well actually a lot of) FIR and IIR filtering, to visualize the temporal structural similarities and differences of TLT relative to SAT (or vice versa). Some FFT's also.

I suggest considering that the atmosphere is changing -- specifically the aerosol burden. Have you looked at India in the DSCOVR imagery? I am just guessing that the dark gray atmosphere http://epic.gsfc.nasa.gov/epic-archive/png/epic_1b_20160112054633_00.png(big image)that moves around, sometimes up to the edge of the Himalayas, sometimes further south over the ocean, is burdened with coal smoke -- and that this is changing fast enough to kerfloozle someone's satellite results. There would be the same issue for the atmosphere coming from northeast China, tho' that will be imaged better in six months.

See Tamino's post for a direct comparison of RSS vs. balloon-borne (RATPAC) observations at similar altitudes, which provides fairly solid evidence that there are instrumentation issues here -- not saying for sure who's right, though I have my suspicions.

OK, humor me a bit longer with my amateur guess. Tamino says:"... Thermometers didn’t change how they measure temperature, nor balloons how they rise through the atmosphere. But satellite instruments have gone through many changes, satellite orbits have altered, and the satellites themselves change over time. I strongly suspect that there’s a serious problem with the satellite data after about the year 2000, as indicated by their divergence from thermometer data...."

Asking again, hoping someone knows -- did the atmosphere change, particularly locally? I look at the DSCOVR imagery showing that dark gray cloud moving around north and eastward from India, day after day.

And I wonder -- are balloon data being taken from that area?If not, it'd be the satellites that would be looking down on that dark gray cloud -- would they get a different result incorporating that in a global result, than the balloon data would?

I dunno. Maybe weather balloon coverage is thoroughly understood but not by me.

The difference between 5.6 and 6 has to do with the fact that UAH USED to do this — “UAH does not yet correct the diurnal drift for satellites carrying Advanced Microwave Sounding Units because they attempt to use these satellites during periods when the diurnal drift is small.”

...and yes... it could be that it affects the diurnal drift near the black clouds coming out of India and China... and the 5.6 data from UAH is telling us how much of it is a difference in location... ? OK... I'm done. No more speculation.

I'm going to wait for Eli and Tamino and Nick Stokes to get together with Po-Chedley to do a paper that clearly needs doing.

I you visit the UAH page http://nsstc.uah.edu/climate/and download the December 2015 Global Temperature Report, you will notice that there is a list of the top 5 warmest years according to UAH data. On the same UAH page is a link entitled "Monthly Average Data".If you calculate the average temperatures using this data you will find that although the order of hottest 3 years is the same, the orders of the fourth ad fifth are not. Moreover the anomalies are different.

So, CIP, EFS, on the one hand, you seem to have bought into the idea that climate disruption remedies should not be pursued until there is observational evidence in the series "proving" impact of CO2 upon climate. On the other, you seem to throw every conceivable doubt-regarding-methodology into the path of observational vehicles for assessing climate measurements which yield a result other than warming. How do you justify this?

If I or someone were to throw a bunch of these observational vehicles into a blind bag and pick them for assessment, independent of what they say, would not you accept their results? Seriously, the posterior distribution of the outcome of an estimate of warming should not be conditional upon the range of that warming. It should be independent of it. Don't you agree? And if you do not, why not? And if you pretend to be rational, what are these other things you condition on?

And what if the prediction of warming does not depend, primarily, upon observational evidence, but, rather, come from physical theory?

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Eli Rabett

Eli Rabett, a not quite failed professorial techno-bunny who finally handed in the keys and retired from his wanna be research university. The students continue to be naive but great people and the administrators continue to vary day-to-day between homicidal and delusional without Eli's help. Eli notices from recent political developments that this behavior is not limited to administrators. His colleagues retain their curious inability to see the holes that they dig for themselves. Prof. Rabett is thankful that they, or at least some of them occasionally heeded his pointing out the implications of the various enthusiasms that rattle around the department and school. Ms. Rabett is thankful that Prof. Rabett occasionally heeds her pointing out that he is nuts.